A vehicle steering system disclosed in Patent Document 1, for example, includes a steering shaft connected to a steering wheel, an intermediate shaft connected to the steering shaft via a cross joint, a pinion shaft connected to the intermediate shaft via another cross joint, and a rack shaft meshed with pinion teeth of the pinion shaft and connected to wheels. Each cross joint is formed of a joint spider having four shaft portions that form a cross shape as a whole. The pinion shaft and the rack shaft constitute a rack-and-pinion mechanism.
In the vehicle steering system, when the steering wheel is steered, the steering torque thereof (rotation of the steering wheel) is sequentially passed through the steering shaft and then intermediate shaft and then transmitted to the pinion shaft, so that the pinion shaft rotates. In association with the rotation of the pinion shaft, the rack shaft steers the wheels while making a linear motion.